Engine piston



July 14, 1925. v1,546,243

M, W. KIMMERLING ENGNE PI STON i *E 1L;

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M. W. KIMMERLING ENGINE PISTON Filed Oct. 23, 1924 2 Sheets-Sheetl 2 Patented July 14, v1925.

' MAXWELL W. KIMMERLING, Vor WASHINGTON; DISTRICT or COLUMBIA ENGINE PISTON.

Application led October 23,1924. Serial No. 745,349.

To all whom t may concern.'

Be it known that I, MAXWELL W. KIM- MERILING, a citizen of the United States, residing at Washington, in the District of Columbia, have invented certain new and useful Improvements in Engine Pistons, of which the following is a specification.

This invention relates to an engine piston, and particularly to a construction embodying a yielding piston head adapted for use in an explosivetype of engine to effect the complete evacuation of burnt gases uponthe exhaust stroke and also to provide a supplemental compression upon the stroke of the piston for compression.

In this construction of piston it is important to provide means wherebythe pistonv head may be readily removed when necessary without the disconnection of the piston rods therefrom or from the engine crank shaft, and the removal of this head permits the' replacement when necessary of either the tension spring or piston rings. Further, in prior constructions on the exhaust stroke of the piston the yielding of the head results in'an untraveled area or space at the end of the c linder which prevents thorough scavengmg of the burnt gases therefrom and from the cylinder head, and to obviate such objections means are provided on the head to compensate for such space and also to enter the head spiace for the ejection of gases therefrom.

' Under the compression stroke the spring tension of the head supplements the piston pressure to secure more even and effective compression while in the firing stroke this tension acts upon the expanding fuel to maintain a constant pressure thereof for substantially the full stroke. Under normal conditions the gas expansion reduces the pressure as the piston head moves outward and the reaction of the spring against the fuel equalizes the pressure within the cylinder to secure the most even and smooth driving effect upon the engine. f

. The invention has for an object to provide a novel and improved construction of engine piston comprising a body having a piston rod connected thereto and a piston head slidably mounted thereon with tension means for projecting said head and securing means accessible at the exposed face of the head for connecting the same to the body.

Another object of the invention is to provide an improved construction of piston head having a curved or spherical pressure faceand longitudinally movable upon the piston rod to enter or travel into the fuel space of the engine head at the exhaust stroke of the piston.

A further object of the invention is to provide anV improved construction of piston comprising ay body and a cooperating head normally projected-therefrom by an interposed spring, together with a yoke slidably'.

mounted upon the wrist pin of the piston rod and detachably connected to the' head by fastening means extending Y therethrough and accessible without disconnection of the piston rod.

Other and further objects and advantages of the invention will be hereinafter set forth and the novel features thereof defined byA the appended claims.

In the drawings Figure 1 is a vertical section showing the application of the invention at the exhaust stroke;

- Figure 2 is a similar view showing the the end of parts inV position for theV compression stroke at the time of liring;

Figure 3 is a central vertical section engine and the size and general configuration of the piston may be adapted for the particular type of engine to which it is to be 1`00 applied.

In the form shown vthe engine 10 is provided With the usual cylinder 11 and the engine head 12 rovided with the fuel or combustion cham r 13 into which a spark plug 14 extends. This chamber has the usual valve connections for intake and exhaust, the latter being shown at 15 and communicating 'with an exhaust passage 16. Within the cylinder the piston `17 is .disposed and this member may be formed of any desired material, preferably of an alumlnum alloy, and iS connected by the rod 18 with the line 7.-7 of .the crank shaft in dthe ordinary manner;

. spherical pressure I cate with unthreading,

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The piston comprises two membersfmovable relatively to each other and a preferred form constitutes the body or sleeve 20 which is formed with inwardly extending bearlings 21 to receive the wrist pin 22 which is clamped upon the rod 18 in the usual manner, as shown at 23.

The pistonor head 17 is slidably mounted on the body and comprises an extended'or face 24 and a skirt portion 25 which is provided' with a series-of apertures 26 effecting a cooling action as well as permitting the introduction of oil to the contacting surfaces between the skirt and the kbody 20. This piston head is also provided with the usual piston rings 27 While disposed between the inner face of the head and the body 20 is a tension spring 28 of suitable strength to normally project the piston head away from the body and maintain such projection to a certain extent even under conditions of compression.

In order to prevent friction in the movementv of this spring and also overheatingI thereof, 4the body 20 is formed at its upper portion with openings 29 which communithe space between the body and head. v

For the purpose of connecting the head to. the connecting rod and body so as to permit the convenient removal of the head whenever desired without disconnection of the rod, ayoke member 30 is connected to the head by means of a fastening device suchl as a bolt 31 extending through the exposed pressure face 24 ofthe head and threaded into the aperture 32 of the yoke. This yoke is seated in an angular recess 38 of the head to prevent rotative movement. In order to.

provide a smooth finish this bolt head maybe seated in a suitable recess 33 and for the further purpose of securing the same against recesses 34 are provided at opposite sides of the bolt and adapted to receive a cotter pin or other securing device as shown at 35 which passes through properly aligned apertures in the head and bolt. The extended walls 36 of the yoke are each provided with an elongated aperture 37 which embraces the wrist pin 22 and permits n a sliding movement of the yoke thereon. These walls 36 are preferably disposed intermediate ofthe bearin 21 and the rod connection with 'the wrist pin and are thusguided in their vertical movement While the extent of travel of the head in itsexpansive and retractive movements is limited by the end walls of the elongated slots 37.5

In the operation of the invention, with the parts in the position shown in Figure l, the

head of the piston extends into the fuel chamber of the engine head and thus more efficiently expels therefrom all burnt ases when the exhaust valve is opened., the plStOli head being at this tinie in its normal condition when not subjected to pressure. Upon the closing of the exhaust valve and the j opening of the intake valve the outward movement of the piston'produces a suction inta-ke of fuel which is materially increased Iowing to the spherical configuration of the tion shown in Figure 2, at which time thecompressed body of fuel acts upon the head causing the same to retract and place the spring under tension, this tension maintaining a greater pressure or compression in the fuel body. Under these conditions the compression of the piston head leaves a space or area at the end of the cylinder and the spherical head compensates for this space as it is adapted to travel more or less into the fuel chamber of the engine head.

When the parts in Figure 2 are 1n position for firing and upon the ring stroke, the compression of the piston head is maintained until the expansion of the fuel causes the compression thereof to be reduced in the travel of the piston and during this travel the'head is projected from the piston body under the spring tension to maintain a practically equal pressure of the exploded gas during the entire travel of the piston From the construction shown it will be seen that this type of piston permits the removal of a head for replacement or repair cf either the spring or rings without y disturbing the rod connections and thus greatly reduces the time required for that purpose and permits access to the piston parts by the simple removal of the engine head as ordinarily for cleaning purposes. Furthermore, the cylindrical construction of this head presents a curved face adapted to travel into the chamber of the engine head and thus most efectually produce the scavenging action upon exhaust. The mounting of the head upon the wrist pin by means of the yoke yprovides an additional guiding function while limiting the extent of the expansive and contractive movements of the spring relative to the body 4of the iston.

It will be seen that the invention presents avery simple, efficient and economical device results in -a piston for internal combustion.

While the details of construction have been specifically shownand described, still the invention is not confined thereto as changes and alterations may-be made therein without departing from the spirit of the invention as defined by the appended claims.

Having thus described my lnvention, what adapted to produce the most .efficient head upon said Wrist pin.

I claim as new and desire to secure by Letters Patent is: p 1

yl. In an engine piston, a body, a piston rod having a wrist pin pivoted upon the body, a piston head slidably mounted upon 2. In an engine piston, .a body, a piston Vrod having' a Wrist pin connected thereto,

a piston rod slidably mounted upon lthe body tension means for projecting said head, depending means carried bysaid head for limiting its movement upon said body byu engagement Withsaid Wrist pin, and securing means for connecting said depending means to the head accessible at the pressure face thereof.

3.In an engine piston, a body,.a piston rod connected thereto and provided with a 'Wrist pin, a piston head slidably mounted upon thebody, tension means for project-` ing said head, securing means for connecting said head to the body accessible at the pressure face of the head, and a member secured to the head and embracing the Wristpin of the connecting rod to limit the relative movement of the head upon the body.

4. In an engine piston, a'body, a piston rod connected thereto, a piston head slidably mounted upon the body, tension "means for projecting said head,a support connected to said head land slidably mounted upon the body, and'a securing device fof said support.

5. In' an engine, a cylinder and cooperating engine head, a piston comprising a bod-y, a piston rod yhaving a Wrist pin mounted thereon, a piston head yieldingly carried by said body and provided with al spherical pressure face disposed to enter and substantially fill fthe head space -beyond the lcylinder, and securing means extending/inward from said face for Idetachably mounting the 6. In 'an engine piston, a body, a pisto rod having a Wrist pin mounted in the body, a head provided with a curved pressure face, a perforated' skirt carried by said head to completelya enclose said body, a tension spring disposed between said body and the inner face of the head, and securing means eXtendin between said face and the Wrist lpin and aving means at the outer face wof. the head for removably connecting the head to said securing means. Y v

An engine piston Acomprising a body n having a wrist pin mounting, a piston head" movable relative to the body, tension' means disposed between the body and head to project thedatter, means within the head for limiting its movement relative to the Wrist pin, and asecuring device -for said limitingrmeans accessible at thel outer face of the head' 'i I v 8. In an engine piston, a body, a'pistor.

rodinouted therein, ahead enclosing saidA t ybody and provided with a spherical pressure face, a tension spring disposed between said body and the innenface of said'head, and a securing bolt extending through said spherical face for connecting the head `to -said Y' 9. I'n an engine piston, a body` a piston rod mounted therein, a head enclosing said body and provided with a spherical pressure face, a tension spring disposed between said body and the inner face of said head, a yoke connecting said head and b'ody and provided with elongated slot-s to permit relative movement of the parts, and a bolt extending through said spherical face and threaded into said'yoke. `J10. In an engine pist-on, a body provided with Wrist pin bearings,-a piston head em-` bracing the same, tension means disposed esI between said body and head, a connecting" member mounted upon the inner face of the. head to limit its travel relative t6 said bearings, andmeans for detachably mounting said member upon the head.

111 In an enginepiston, a piston head, a connecting member mounted upon the inner rface of the head, an attaching device for said member having operatingv means accessible at the outer surface 'of said face, and locking means mounted in said surface and extending through said operating means., V

12. In an engine piston, a body, a connect- ,I ing rod` having a Wrist pin pivotedin bearings atv opposite sides .of said body, a head having-a skirt embracing said body,a connection from said head comprising parallel slotted flanges disposed between the `conneotj ingrod and said bearing,- and an attaching device extending through the head to saidY connection.

13. In an engine piston, a body having a.4`

solid cylindrical wall andv provided at oppo- Q site sides with bearings and intermediate 1 openings through the body, a head provided with a perforated skirt contacting with said Wall, a connecting rod mounted in said bearings, and -means for vd'etacllably connecting the `head to said body. f

, 14. In an engine piston, a body, a connecting rod provided witha Wrist pin pivotally mounted therein, a cylindrical head enclosing said body, a tension Spring ,disposed Within said head to normally support the same `from said body, a yyolneseated in said headagainst rotation andprovided with slotted Han es embracing said wrist pin, and 1 a securing olt extendin through the presl sure face of said head an threaded into saidJ l yoke.

15. In an engine piston, a body, a connecting rodprovided with a wrist pinpivotally mounted therein, a cylindrical Ahead enclos-v ing said body, a tension spring disposed 5 Within said head to normally support the same pressure face upon said head providedwith' a central recess, an attaching bolt threaded 1d into 'said yoke and having itsY head seated in` said recess, and a locking device insertable through saidfrecess to lretain the bolt head against rotation;-

in testimony whereof I aix my signature. l vMAXWELL W.- KMMERLING. 

